|
|
||||||||
The Journal of Neurophysiology Vol. 85 No. 6 June 2001, pp. 2461-2467
Copyright ©2001 by the American Physiological Society
Department of Neurobiology, UCLA School of Medicine, Los Angeles, California 90095-1763
Shao, Xuesi M. and
Jack L. Feldman.
Mechanisms Underlying Regulation of Respiratory Pattern by
Nicotine in PreBötzinger Complex. J. Neurophysiol. 85: 2461-2467, 2001. Cholinergic
neurotransmission plays a role in regulation of respiratory pattern.
Nicotine from cigarette smoke affects respiration and is a risk factor
for sudden infant death syndrome (SIDS) and sleep-disordered breathing.
The cellular and synaptic mechanisms underlying this regulation are not
understood. Using a medullary slice preparation from neonatal rat that
contains the preBötzinger Complex (preBötC), the
hypothesized site for respiratory rhythm generation, and generates
respiratory-related rhythm in vitro, we examined the effects of
nicotine on excitatory neurotransmission affecting inspiratory neurons
in preBötC and on the respiratory-related motor activity from
hypoglossal nerve (XIIn). Microinjection of nicotine into preBötC
increased respiratory frequency and decreased the amplitude of
inspiratory bursts, whereas when injected into XII nucleus induced a
tonic activity and an increase in amplitude but not in frequency of
inspiratory bursts from XIIn. Bath application of nicotine (0.2-0.5
µM, approximately the arterial blood nicotine concentration
immediately after smoking a cigarette) increased respiratory frequency
up to 280% of control in a concentration-dependent manner. Nicotine
decreased the amplitude to 82% and increased the duration to 124% of
XIIn inspiratory bursts. In voltage-clamped preBötC inspiratory
neurons (including neurons with pacemaker properties), nicotine induced
a tonic inward current of
19.4 ± 13.4 pA associated with an
increase in baseline noise. Spontaneous excitatory postsynaptic
currents (sEPSCs) present during the expiratory period increased in
frequency to 176% and in amplitude to 117% of control values; the
phasic inspiratory drive inward currents decreased in amplitude to 66%
and in duration to 89% of control values. The effects of nicotine were
blocked by mecamylamine (Meca). The inspiratory drive current and
sEPSCs were completely eliminated by
6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) in the presence or absence
of nicotine. In the presence of tetrodotoxin (TTX), low concentrations
of nicotine did not induce any tonic current or any increase in
baseline noise, nor affect the input resistance in inspiratory neurons.
In this study, we demonstrated that nicotine increased respiratory
frequency and regulated respiratory pattern by modulating the
excitatory neurotransmission in preBötC. Activation of nicotinic
acetylcholine receptors (nAChRs) enhanced the tonic excitatory synaptic
input to inspiratory neurons including pacemaker neurons and at the
same time, inhibited the phasic excitatory coupling between these
neurons. These mechanisms may account for the cholinergic regulation of
respiratory frequency and pattern.
This article has been cited by other articles:
![]() |
C. Coddou, E. Bravo, and J. Eugenin Alterations in cholinergic sensitivity of respiratory neurons induced by pre-natal nicotine: a mechanism for respiratory dysfunction in neonatal mice Phil Trans R Soc B, September 12, 2009; 364(1529): 2527 - 2535. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. M. Pilowsky, M. S. Y. Lung, D. Spirovski, and S. McMullan Differential regulation of the central neural cardiorespiratory system by metabotropic neurotransmitters Phil Trans R Soc B, September 12, 2009; 364(1529): 2537 - 2552. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. V. Volgin, I. Rukhadze, and L. Kubin Hypoglossal premotor neurons of the intermediate medullary reticular region express cholinergic markers J Appl Physiol, November 1, 2008; 105(5): 1576 - 1584. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. M. Shao, W. Tan, J. Xiu, N. Puskar, C. Fonck, H. A. Lester, and J. L. Feldman {alpha}4* Nicotinic Receptors in preBotzinger Complex Mediate Cholinergic/Nicotinic Modulation of Respiratory Rhythm J. Neurosci., January 9, 2008; 28(2): 519 - 528. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Liu, S. Sood, H. Liu, and R. L Horner Opposing muscarinic and nicotinic modulation of hypoglossal motor output to genioglossus muscle in rats in vivo J. Physiol., June 15, 2005; 565(3): 965 - 980. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Saywell and J. L. Feldman Dynamic interactions of excitatory and inhibitory inputs in hypoglossal motoneurones: respiratory phasing and modulation by PKA J. Physiol., February 1, 2004; 554(3): 879 - 889. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Caldirola, L. Bellodi, A. Caumo, G. Migliarese, and G. Perna Approximate Entropy of Respiratory Patterns in Panic Disorder Am J Psychiatry, January 1, 2004; 161(1): 79 - 87. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. M Shao, Q. Ge, and J. L Feldman Modulation of AMPA receptors by cAMP-dependent protein kinase in PreBotzinger complex inspiratory neurons regulates respiratory rhythm in the rat J. Physiol., March 1, 2003; 547(2): 543 - 553. [Abstract] [Full Text] [PDF] |
||||
![]() |
A B Chang, S J Wilson, I B Masters, M Yuill, J Williams, G Williams, and M Hubbard Altered arousal response in infants exposed to cigarette smoke Arch. Dis. Child., January 1, 2003; 88(1): 30 - 33. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. M. Shao and J. L. Feldman Pharmacology of Nicotinic Receptors in PreBotzinger Complex That Mediate Modulation of Respiratory Pattern J Neurophysiol, October 1, 2002; 88(4): 1851 - 1858. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Cohen, Z.-Y. Han, R. Grailhe, J. Gallego, C. Gaultier, J.-P. Changeux, and H. Lagercrantz beta 2 nicotinic acetylcholine receptor subunit modulates protective responses to stress: A receptor basis for sleep-disordered breathing after nicotine exposure PNAS, October 1, 2002; 99(20): 13272 - 13277. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M Robinson, K. C Peebles, H. Kwok, B. M Adams, L.-L. Clarke, G. A Woollard, and G. D Funk Prenatal nicotine exposure increases apnoea and reduces nicotinic potentiation of hypoglossal inspiratory output in mice J. Physiol., February 1, 2002; 538(3): 957 - 973. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |